The present invention relates to moist pellet feed for breeding fish, and more particularly to moist pellet feed for breeding fishes comprising a raw feed and a powdery mixed feed, wherein the amount of the raw feed is equal to or more than that of the powdery mixed feed.
Hitherto, there have been generally known dry pellet feed for breeding fish. However, the dry pellet feed having no water is undesirable as feed for breeding saltwater fish such as a yellowtail, since the saltwater fish drink seawater and excrete excess body salinity through the gill and water is supplied through the gill. Dry pellet feeds having no water are not suitable for such fish. Therefore, it is desirable to develop various moist pellet feeds containing a lot of water.
Moist pellets contain a lot of water, and are prepared by admixing raw feeds, i.e., small fish such as saurels, sardines, saurys, mackerels and sand eels, which may be raw or refrigerated, with powdery mixed feeds composed of fish meals, minerals, vegetable oil cakes, grains, chaffs and brans and the like, and a binding agent, and by pelletizing the mixture. The raw feed may be minced, sliced or filleted. The moisture contained in the moist pellets is the moisture of the raw feed (fish) and the moisure in the mixed feeds. In case of moist pellets composed of the raw feeds and the mixed feeds in a weight ratio of 5:5, the water content in the moist pellets is about 50% by weight. (Generally, water content in the raw feeds are about 75 to about 85% by weight). The present invention relates to such moist pellet feeds for breeding fish, which have a high water content.
The moist pellets have the advantage that they do not readily go to pieces in seawater and reduce the death rate of fish. In order to obtain the above-mentioned advantage, however, it is usually required to include a binding agent in the moist pellets. Examples of the binding agents are, for instance, sodium alginate, guar gum, sodium polyacrylate, carboxymethyl cellulose, and the like. However, these binding agents have the disadvantage that when moist pellets have raw feed in an amount of not less than 50% by weight, the binding property is insufficient due to a lot of moisture in the pellets with the pellets becoming sticky and adhering to each other, and thus moist pellets having a form that fish can easily eat are not obtained.
As aforementioned, there have not been provided final products having sufficient practicality, that is, there have been no economical moist pellets containing not less than 50% by weight of raw feeds, and having sufficient hardness to be easily eaten by fish.
The present inventors have paid attention to binding agents which perform the most important function in the moist pellet feeds for breeding fish, particularly, to a carboxymethyl cellulose which has been most widely used as the binding agent in recent days.
An object of the present invention is to provide economical, moist pellet feed for breeding fish, having a sufficient hardness and no stickiness for preventing adhesion between the pellets, and having a high content of raw feeds.
This and other objects of the present invention will become apparent from the following description given hereinafter.